In recent years, mobile terminals, such as a cellular phone, have become more sophisticated in functionality, and for example, are required to be adapted to broadband communication so as to be capable of coping with frequency bands of a plurality of wireless communication systems. Further, the mobile terminals are required e.g. to be reduced in size so as to be easily portable.
Some mobile terminals have a plurality of antennas in order to be adapted to broadband communication. For example, a mobile terminal covers the communication bands by the plurality of antennas, respectively, to thereby realize broadband communication. In this case, a space within the mobile terminal for mounting the antennas becomes larger, which increases the size of the mobile terminal.
Further, the antenna has a trade-off relation between the frequency of wireless communication and the antenna size. For example, to cover a low frequency band by a plate antenna, the antenna is increased in size, which increases the size of a mobile terminal.
Conventionally, there have been proposed an antenna device which is reduced in size, and is adapted to low frequencies and a wider bandwidth, and a mobile electronic device equipped with the antenna device (see e.g. Japanese Laid-Open Patent Publication No. 2006-279530).
As described above, the antenna has a problem that to cover broadband communication, the size thereof is increased.